The present disclosure relates to a light source apparatus including a light-emitting diode or the like as a light source thereof and relates to a display apparatus including a light source apparatus for illuminating a display portion from the back side.
Recently, thin display apparatuses such as a liquid-crystal display apparatus and a plasma display have been proposed and put into practical use.
In particular, liquid-crystal display apparatuses using liquid-crystal display panels can be driven with low power consumption, and large liquid-crystal display panels can be manufactured at low cost. Accordingly, those liquid-crystal display apparatuses have been used widely, and technological research and development thereof have been made.
Such light-emitting display apparatuses typically employ a backlight system using a backlight apparatus in which a whole surface of a light transmissive liquid-crystal display panel including a color filter is illuminated with light from the back side to display color images.
An Edge-light system and a direct system are typically employed as the structures for the backlight apparatus.
In the edge-light system, a light source (light-emitting diode or fluorescent lamp) emits light toward the end surface of a light-guiding plate provided to the lower surface of a light-diffusing plate from a direction perpendicular to the illuminating direction, thereby obtaining a surface light source.
In the direct system, a light source (light-emitting diode or fluorescent lamp) provided in matrix shape directly under the light diffusing plate emits light in the direction vertical to the light diffusing plate.
Since liquid-crystal display apparatuses may require improved brightness, backlight apparatuses may also require improved brightness.
Japanese Unexamined Patent Application Publication No. H10-253807, for example, discloses an edge-light system including a light transmissive film with a prism attached thereto in order to improve brightness.
Since light obliquely emitted from a light exit plane of a light-guiding plate can be brought close to the normal direction of the light exit plane by providing the light transmissive film with the prism attached as described above, the brightness of light in the normal direction of the light exit plane can be increased.
However, according to Japanese Unexamined Patent Application Publication No. H10-253807, the prism is disposed such that light is refracted at boundary surfaces, when light emitted from the light-guiding plate is incident on the prism on the light transmissive film and when light outgoes from the prism, respectively. When light is refracted at the boundary surfaces of the prism, light is not only refracted but also reflected on the boundary surfaces of the prism and returns. Therefore, an amount of light is reduced to the extent of the reflected light.
With such light loss, brightness improvement may be prevented.
It is desirable to provide a light source apparatus in which brightness can be improved and to provide a display apparatus including the light source apparatus.